We propose to study the DNA sequence organization, transcription control, and evolutionary conservation of the silk fibroin gene and a large amount of neighboring DNA on either side of it from the animal genome. In particular, we will test whether the neighboring DNA is transcribed into a large precursor to fibroin mRNA or into unrelated RNA, and look for RNA splicing in this system. We will localize the initiation and termination sites for fibroin gene transcription. A search for proteins binding specifically to the neighboring DNA will also be make. The action of homologous RNA polymerase II on the cloned DNA will be studied. The DNA near the gene will be examined for repeated sequences and palindromes. Its conservation of drift in evolution will be tested by cloning fibroin gene regions from related animals and comparing their sequences by annealing techniques.